Herpes simplex virus (hsv) with modified tropism, uses and process of preparation thereof

ABSTRACT

A modified Herpes Simplex Virus (HSV), which has a portion of gD (glycoprotein D) of the glycoproteic envelope deleted and a heterologous single chain antibody inserted in place of such deleted portion; the modified HSV is capable of infecting cells through receptor HER2/ErbB2 but not through receptors HVEM/HveA and nectin1/HveC; uses of the modified HSV and a process of the preparation thereof are also disclosed.

FIELD OF INVENTION

The present invention relates to a modified herpes simplex virus (HSV),uses of the modified HSV, a pharmaceutical preparation and a process ofpreparing a modified HSV.

BACKGROUND

A novel frontier in the treatment of tumors is oncolytic virotherapy,whereby a replication competent virus infects the tumor cells, spreadsfrom cell to cell of the tumor and destroys them. Two such tumors aremammary and ovary cancers, that afflict animals such as humans. About30% of human mammary tumors, as well as some ovary tumors, are highlymalignant and metastatic.

These tumors owe their high malignancy and metastaticity to theexpression of a specific cell surface molecule receptor, named HER2,that belongs to the family of epidermal growth factor receptors, and aregenerally treated with surgery or combined surgery and radiotherapy orchemotherapy.

HSV is a pathogen virus for mammalian cells [HSV-1 is e.g. described inEjercito, P. M., et al. (1968). J Gen Virol 2:357 and its genome hasaccession number NC-001806 (GenBank)].

HSV enters cells by a multistep process. The first step is attachment tothe cell surface, mediated by interaction the glycoproteins gB and gC(Laquerre S., Argnani R., Anderson D. B., Zucchini S., Manservigi R.,Glorioso J. C. (1998), J. Virol. 72(7):6119-30). This is followed by themore specific interaction of the virion envelope glycoprotein D (gD)with one of its entry receptors: nectin1/HveC, HVEM/HveA, and O-linkedsulphated moieties of heparan sulphate (Spear P. G., Eisenberg R. J.,Cohen G. H., (2000) Virology 275:1-9) (Campadelli-Fiume G., Cocchi F.,Menotti L., Lopez M. (2000) Reviews in Medical Virology, 10:305-319)(Campadelli-Fiume G. et al. (2007) Rev. Med. Virol., 17:313-326) (theGenBank codes for the receptors are the followings: nectin1 alphaAF060231, nectin1 beta AF110314, HVEM U70321).

In recent years, there have been attempts to use genetically engineeredHSVs as oncolytic agents mainly to treat malignant glioma. Inasmuch aswild-type viruses are virulent, target and destroy many different cellsand tissues, the candidate oncolytic HSVs have been highly attenuated.The viruses that have reached clinical trials were made dependent fortheir replication upon the dividing tumor cell by the deletion of twoHSV genes, namely the gamma1 43.5 gene—which encodes the ICP34.5 proteinwhose role is to preclude the shut off of protein synthesis in infectedcells, and the UL39 gene—which encodes the large subunit ofribonucleotide reductase. These viruses are marred by low ability toreplicate, even in dividing cells, a feature that results in twonegative effects. First, administration of such viruses to tumors failsto produce high yield of progeny viruses, capable of spreading from cellto cell of the tumor itself, and thus to amplify the response to anygiven therapeutic dose of the virus. Second, the viruses are difficultto grow and can hardly be produced in large scale (10⁸-10⁹ plaquesforming units PFU/ml) to yield the amount of virus required for clinicalapplications. Furthermore, the preserved ability of the virus to bind toany cell bearing one the natural receptors for the HSV subtracts thevirus to the tumor tissues that most need it and diminishes thetherapeutic effect of tumor cell killing, and may exert undesiredinfection of non cancer tissues and cells, including their death byapoptosis. We note that, even if these viruses were retargeted totumor-specific receptors—they are nonetheless highly attenuated.

Recently HSV retargeted to specific receptors have been geneticallyengineered so that they can infect cells that need to be destroyed whilemaintaining high capacity to replicate and spread from cell to cell.Though such viruses have a good ability to spread among tumor cells,they still undesirably infect non cancer tissues and cells.

Patent application having publication number WO2004/033639, whosecontent is herein fully included, discloses a recombinant HSV, whichexpresses on its glycoproteic envelope a natural cytokine. Though theuse of recombinant HSV of this type has been proposed for treatingtumors, it is important to stress that: the targeted receptor hasnatural ligand of a small size such that it can be readily inserted ingD, and the proposed recombinant HSV is still capable of interactingwith receptors nectin1/HveC and HVEM/HveA. In particular, WO2004/033639fails to identify mutations that would result in a recombinant HSV whichis not anymore capable of binding nectin1/HveC and is capable of bindingreceptors (such as HER2/ErbB2) of diseased cells.

It follows that a need in the art still exists for viral therapeuticagents targeting selectively cells that need to be destroyed. Inparticular a need exists for viral therapeutic agents targetingreceptors that have no natural ligand, and are overexpressed orselectively expressed in diseased cells, such as cancer cells.

SUMMARY

It is an object of the present invention to provide a modified HSVdesigned to at least partly eliminate the drawbacks of the known art,and which, at the same time, are easy to implement.

Further objects of the present invention are to provide uses of thementioned modified HSV, pharmaceutical preparations, and a process ofpreparing the modified HSV.

All references (e.g. patents, patent applications, publications, GenBanksequences, and other published materials) referred to throughout theentire present text, unless noted otherwise, are herein entirelyincorporated for completeness of disclosure (incorporated by reference).

Unless the contrary is explicitly specified, the following terms havethe hereinafter indicated meaning.

As used herein, “single chain antibody” (scFv) refers to “properlycalled” single chain antibody (i.e. having two domains connected by alinker) or other similar antibody derivatives (e.g. Single V-Typedomains). Advantageously, the “single chain antibodies” are “properlycalled” single chain antibodies. A non-limiting example of a “properlycalled” single chain antibody is scHER2 (disclosed in the below reportedexamples).

As used herein, “percentage of identity” or “% identity” between twoaminoacid or nucleotide sequences refers to the percentage of aminoacidor nucleotide residues identical in corresponding positions in the twosequences aligned optimally.

For establishing the “percentage of identity” of the two aminoacid ornucleotide sequences the sequences are aligned; for having an optimalalignment, gaps (deletions or insertions—which may possibly be locatedat the extremes of the sequences) are possible. The aminoacid ornucleotide residues are compared. Where a position in the first sequenceis occupied by the same aminoacid or nucleotide residue which occupiesthe corresponding position in the second sequence, the molecules areidentical in that position. The “percentage of identity” between twosequences is a function of the number of shared identical positions ofthe sequences [i.e. % identity=(number of identical positions/number oftotal positions×100].

In accordance to advantageous embodiments, the sequences have the samelength (same number of aminoacid residues or nucleotides).

Advantageously, the compared sequences do not have gaps.

The percentage of identity may be obtained using mathematicalalgorithms. A non limiting example of a mathematical algorithm, which isused to compare two sequences is the algorithm of Karlin and Altschul[Proc. Natl. Acad. Sci. USA 87 (1990) 2264-2268] modified by Karlin andAltschul [Proc. Natl. Acad. Sci. USA 90 (1993) 5873-5877].

In order to obtain alignments also in presence of one or more gaps, itis possible to use methods that give a relatively high penalty for eachgap and a lower penalty for each further aminoacid or nucleotide residue(such a further aminoacid or nucleotide residue is defined as anextension of the gap). High penalties result, obviously, in optimalalignments with a lower number of gaps.

An example of a program (software) designed to make such a type ofalignment is the BLAST program as disclosed in Altschul, et al., NucleicAcids Res. 25 (1997) 3389-3402. For this purpose BLASTn and BLASTpprograms may be used with default parameters. In the BLAST programsmatrix BLOSUM62 is usually used.

An advantageous and non-limiting example of a program for obtaining anoptimal alignment is GCG Winsconsin Bestfit package (University ofWinsconsin, USA; Devereux et al., 1984, Nucleic Acids Research 12:387).Also in this case, the default parameters (which provide a penalty of−12 for each gap and a penalty of −4 for each extension) are used.

As used herein, “percentage of homology” or “% homology” between twoaminoacid or nucleotide sequences refers to the percentage of aminoacidor nucleotide residues homologous in corresponding positions in the twooptimally aligned sequences.

The “percentage of homology” between two sequences is established in amanner substantially identical to what has been above described withreference to the determination of the “percentage of identity” exceptfor the fact that in the calculation also homologous positions and notonly identical positions are considered.

As far as nucleotide sequences are concerned, two homologous positionsmay have two different nucleotides, but such two nucleotides, within therespective codon, codify the same aminoacid.

As far as aminoacid sequences are concerned, two homologous positionshave two identical or homologous aminoacid. Homologous aminoacidresidues have similar chemical-physical properties, for example,aminoacids belonging to a same group: aromatic (Phe, Trp, Tyr), acid(Glu, Asp), polar (Gln, Asn), basic (Lys, Arg, His), aliphatic (Ala,Leu, Ile, Val), with a hydroxyl group (Ser, Thr), with a short lateralchain (Gly, Ala, Ser, Thr, Met). It is expected that substitutionsbetween such homologous aminoacids do not change a protein phenotype(aminoacid conservative substitutions).

Specific examples of conservative substitutions in this technical fieldare disclosed in several references [e.g. Bowie et al., Science,247:1306-1310 (1990)].

Further examples of programs and/or articles relating to theestablishment of optimal alignments and/or percentages of homologyand/or identity are cited, for example, in US2008003202, US2007093443,WO2006048777, WO2007149406.

As used herein, “corresponding position” refers to a position of aaminoacid or nucleotide sequence corresponding (facing), after analignment has been performed, to a given position of a referencesequence.

For example, a position corresponding to a given position of gD havingSEQ ID NO:1 may be identified aligning SEQ ID NO:1 with a peptidesequence of interest; the alignment may be obtained either manually oras above disclosed with reference to the determination of the percentageof identity.

As used herein, “a naked polypeptide chain” refers to a polypeptide thatis not post-translationally modified or otherwise chemically modified,but contains only covalently linked aminoacids.

As used herein, “ligand capable of binding in specific conditions areceptor” refers to a ligand which, when inserted in HSV by means ofmolecular biology techniques, permits the HSV to penetrate in a cell viathe interaction with that receptor, which the ligand is designed tobind. In particular, the ligand is capable of binding in specificconditions a receptor, when the HSV, which contains it, is capable ofinteracting with that receptor passing the tests disclosed in belowreported example 5 or analogous tests (with different receptors).

As used herein, “capability of HSV (in particular the modified HSV) ofinteracting with a receptor” refers to the capability of the HSV ofpenetrating in a cell via the interaction with that receptor. Inparticular, also in this case, this capability is evaluated by means ofthe tests disclosed in below reported example 5 or analogous tests (fordifferent receptors).

BRIEF DESCRIPTION OF THE FIGURES

Non-limiting embodiments of the present invention will be described byway of example with reference to the accompanying drawings, in which:

FIG. 1 A shows schematic representation of the recombinant HSV-BACgenomes described in this invention. The backbone ofgDminus-EGFP-HSV-BAC is shown as example. The backbone ofgDminus-EGFP-HSV-BAC is shown. The HSV-BACs derive from pYEbac102Tanaka, M., H. Kagawa, Y. Yamanashi, T. Sata, and Y. Kawaguchi. 2003.Construction of an excisable bacterial artificial chromosome containinga full-length infectious clone of herpes simplex virus type 1: virusesreconstituted from the clone exhibit wild-type properties in vitro andin vivo. J Virol 77:1382-91. (Tanaka, 2003 #672), that carriespBeloBACll sequences inserted between UL3 and UL4. IngDminus-EGFP-HSV-BAC the reporter cassette (a27-EGFP) is inserted in theBAC sequences. gDminus-LacZ-HSV-BAC has the same structure, but carriesLacZ in place of EGFP.

FIG. 1B shows a schematic representations of linear maps of wt-gD (a)and the gD chimeric proteins: (b) gD of recombinant R-LM31, carryingsubstitution at amino acid residue 34; (c) gD of recombinant R-LM39,carrying mutations at amino acid residues 34, 215, 222 and 223; (d) gDof recombinant R-LM113, carrying scHER2L in place of amino acid residues6-38; (e) gD of recombinant R-LM249, carrying LscHER2L in place of aminoacid residues 61-218. Bold numbers indicate the length in amino acidresidues of each fragment. Plain numbers refer to amino acid residuesaccording to wt-gD coordinates. L, linkers. TM, transmembrane domain ofgD. V_(H) and V_(L), heavy- and light-chain variable domains of theanti-HER2/neu antibody 4D5. Δ, deletion. Bars are drawn to scale.

FIG. 2 shows that the recombinant virus R-LM31 is not detargeted fromnectin1 receptor. Micrographs of receptor negative J cells (A), andJ-HER2 (B), J-hNectin1 (C) and J-mNectin1 (D) expressing human HER2, andhuman or murine nectin1, respectively, were exposed to R-LM31 at 10PFU/cell. Infection was monitored as β-galactosidase activity by in situX-gal staining 16 h following infection. E. Electrophoretic mobility ofwt and chimeric gDs expressed in SKOV3 cells infected with R-LM5,R-LM13, R-LM31, R-LM39, R-LM113 and R-LM249 recombinant viruses.Infected cell lysates were separated by SDS-PAGE, transferred tonitrocellulose membranes, and visualized by enhanced chemioluminescence.Numbers to the left represent migration positions of molecular massmarkers (in kilodaltons). Arrows indicate the apparent electrophoreticmobility of the wt or chimeric gDs. From bottom to top, wild-type gD(wt-gD) expressed by R-LM5 recombinant virus, gD(Δ61-218)-LscHER2Lexpressed by R-LM249 recombinant virus, gD(Δ6-38)-scHER2L expressed byR-LM113 recombinant virus. The migration of gD-scHER2L expressed byR-LM13, R-LM31 and R-LM39 is indistinguishable from that ofgD(Δ6-38)-scHER2L.

FIG. 3 shows infection of an array of cell lines with R-LM113 andR-LM249 recombinant viruses. Monolayers of the indicated cell lines wereinfected at 5 PFU/cell, and EGFP reporter gene expression was measured24 later by means of a fluorometer. Numbers to the left indicate EGFPintensity in arbitrary units.

FIG. 4 shows the growth of R-LM39, R-LM113 and R-LM249 recombinants andof control viruses R-LM5 and R-LM13. (A to G) Replicate cultures of J(A), J-Nectin1 (B), J-HVEM (C), J-HER2 (D), SKOV3 (E), 1-143 tk⁻ (F), orHEp-2 (G) cells were infected with recombinant viruses R-LM5 (▪), R-LM13(), R-LM39 (Δ), R-LM113 (×) or R-LM249 (▴) at 1 PFU/cell. Progeny viruswas harvested at 3, 24, and 48 h after infection and titrated in SKOV3cells.

FIG. 5 shows the block of infection of SKOV3 cells with R-LM39 (A),R-LM113 (B) or R-LM249 (C) by antibodies to HER2 (Herceptin) or nectin1(R1.302). SKOV3 cells were preincubated with the indicatedconcentrations of purified IgG from Herceptin (Δ), R1.302 (◯) or thecombination of Herceptin plus R1.302 () or irrelevant mouse IgGs (×)for 2 h at 4° C. Virus was added to the antibody containing medium andallowed to adsorb to the cells for 90 min at 4° C. Infection wasmonitored 16 h later as EGFP expression. One hundred percent indicatesthe EGFP readings in untreated virus-infected cultures.

FIG. 6A shows inhibition of cell-to-cell spread by Herceptin. SKOV3cells infected with serial dilutions of the indicated viruses wereoverlaid with medium containing with 1% Seaplaque Agarose±10 μg/mlHerceptin. Individual plaques were photographed at 48 h, and the plaqueareas were measured by means of the Photoshop Histogram tool program andexpressed as pixels×10³. For each virus, the areas of 4 or 5 plaqueswere measured. Histograms represent averages; error bars, standarddeviations.

FIG. 6B shows representative plaques referred to with regard to FIG. 6A.

FIGS. 7 to 15 show maps of the following plasmids: pLM5, pLM13 (scHER2Lbetween aa 24 and 25 of mature gD), pLM31 (obtained by mutagenesis ofpLM13 to introduce the V34S substitution), pS31 (shuttle plasmidobtained by subcloning of the NruI-PmeI fragment from pLM31 into SmaI ofpST76KSR), pS39 (shuttle plasmid obtained by mutagenesis of pS31 withprimer gD_(—)215G-222N-223I_PvuI), pLM113 (carries the sequence codinggD where aa 6-38 of the mature protein are replaced by scHER2L), pS113(shuttle plasmid obtained by subcloning of the NruI-PmeI fragment frompLM113 into SmaI of pST76KSR), pLM249 (carries the sequence coding gDwhere aa 61-218 of the mature protein are replaced by scHER2 flanked bylinkers), pS249 (shuttle plasmid obtained by subcloning of the NruI-PmeIfragment from pLM249 into SmaI of pST76KSR), respectively: underlinedbold italic numbers indicate coordinates in the final complete plasmid;plain font numbers indicate coordinates in original vector andfragments.

FIG. 16 shows the cytotoxic activity of R-LM113 and R-LM249 recombinantscompared to R-LM5 control virus. Histograms represent the the totalnumbers of cells (y axis: cell number×10̂4). For each sample of infected,cells both the adherent (a) and detached (d) fractions of cells werecounted. The hatched parts of the histograms represent the fraction ofnonviable cells (Erythrosin B positive), and the corresponding valuesare indicated in the percentage values over the histograms. NI, noninfected control cells.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

According to a first aspect of the present invention there is provided amodified herpes simplex virus (HSV) comprising a glycoproteic envelope,which has an heterologous peptide ligand capable of binding in specificconditions a given receptor expressed by diseased cells andsubstantially not (or little) expressed by non-diseased cells. Theglycoproteic envelope being so modified that the capability of themodified HSV of binding in specific conditions receptor nectin1/HveC isreduced (with respect to HSV wild type). Advantageously, the capabilityof the modified HSV of binding in specific conditions receptornectin1/HveC is substantially ablated.

According to some preferred embodiments, the capability of the modifiedHSV of binding in specific conditions receptor HVEM/HveA is reduced,advantageously substantially ablated.

The illustrative embodiments are disclosed using as an exemplary virus amember of the Herpesviridae family, HSV-1.

HSV-1 and HSV-2 are herpes simplex viruses. The subject matter of thepresent invention extends to any member of the Herpesviridae family andis not limited to the exemplary embodiments disclosed in the examples.Many HSV are known in the art. Such viruses may contain one or moremutated genes. Examples of recombinant viruses containing heterologousgene and methods of making and using such viruses are described in U.S.Pat. No. 5,599,691. Heterologous genes include genes encoding markerproteins (such as red or green fluorescent proteins or variationsthereof, luciferase or β-galactosidase), which allow detection ofinfected cells expressing the protein.

The modified HSV herein provided has the advantage of maintaining arelevant part of the infectivity of the wild type virus.

According to specific embodiments, the peptide ligand is inserted in gD(glycoprotein D) of the glycoproteic envelope of HSV. A portion of gD isdeleted. Advantageously, the peptide ligand is inserted in place of thedeleted portion, in particular, so that the peptide ligand and gD form afusion protein.

Usually, (mature) wild type gD has the peptide sequence SEQ ID NO:1.

Wild type gD derives from a precursor, which has peptide sequence SEQ IDNO:34.

The mentioned precursor is codified by the nucleotide sequence SEQ IDNO:35.

According to some embodiments of the present invention, gD, before it ismodified, has at least 50%, 60%, 70%, 80%, 85%, 90%, 95% or 100%homology, advantageously identity, with respect to SEQ ID NO:1.

According to some embodiments, the portion, which extends betweenpositions corresponding to 40 to 61, on the one side, and 210 to 218, onthe other side, is deleted. Advantageously, the deleted portion extendsbetween positions corresponding to 61, on the one side, and 218, on theother side.

Herein, loci (positions) of the peptide sequences modified ornon-modified are identified with reference to a aminoacid numbering ofaminoacid residues in corresponding positions of a unmodified (mature)wild type gD as identified by SEQ ID NO:1. Corresponding positions maybe identified by aligning the unmodified residues (see above). Forexample, we hereinafter report the numbering of sequences of wild typegD (SEQ ID NO:1) and its precursor (SEQ ID NO:34)

SEQ ID NO: 1KYALADASLK MADPNRFRGK DLPVLDQLTD PPGVRRVYHI QAGLPDPFQP PSLPITVYYA 60VLERACRSVL LNAPSEAPQI VRGASEDVRK QPYNLTIAWF RMGGNCAIPI TVMEYTECSY 120NKSLGACPIR TQPRWNYYDS FSAVSEDNLG FLMHAPAFET AGTYLRLVKI NDWTEITQFI 180LEHRAKGSCK YALPLRIPPS ACLSPQAYQQ GVTVDSIGML PRFIPENQRT VAVYSLKIAG 240WHGPKAPYTS TLLPPELSET PNATQPELAP EDPEDSALLE DPVGTVAPQI PPNWHIPSIQ 300DAATPYHPPA TPNNMGLIAG AVGGSLLAAL VICGIVYWMR RRTQKAPKRI RLPHIREDDQ 360PSSHQPLFY 369 SEQ ID NO: 34 MGGAAARLGA VILFVVIVGL HGVRGKYALADASLK MADPNRFRGK DLPVLDQLTD PPGVRRVYHI QAGLPDPFQP PSLPITVYYA 60VLERACRSVL LNAPSEAPQI VRGASEDVRK QPYNLTIAWF RMGGNCAIPI TVMEYTECSY 120NKSLGACPIR TQPRWNYYDS FSAVSEDNLG FLMHAPAFET AGTYLRLVKI NDWTEITQFI  180LEHRAKGSCK YALPLRIPPS ACLSPQAYQQ GVTVDSIGML PRFIPENQRT VAVYSLKIAG 240WHGPKAPYTS TLLPPELSET PNATQPELAP EDPEDSALLE DPVGTVAPQI PPNWHIPSIQ 300DAATPYHPPA TPNNMGLIAG AVGGSLLAAL VICGIVYWMR RRTQKAPKRI RLPHIREDDQ 360PSSHQPLFY 369

According to some embodiments, the deleted portion extends betweenpositions corresponding to 1 to 8, an the one side, and 38 to 55, on theother side. Advantageously, the deleted portion is located betweenpositions corresponding to 6, on the one side, and 38, on the otherside.

The aforementioned peptide ligand is any type of suitable ligand knownin the art, for example a cytokine, a growth factor, a derivative ofmonoclonal antibody or, advantageously, a single chain antibody.

According to some specific embodiments, the peptide ligand is capable ofbinding in specific conditions the given receptor, which has at least70%, 80%, 90%, 95% or 100% homology, advantageously identity, withrespect to receptor HER2/ErbB2.

HER2/ErbB2 is a receptor which is overexpressed by, e.g., ovary tumor,mammary tumor, stomach tumor and salivary glands tumor cells (Hynes N.E. and H. A. Lane. “ERBB receptors and cancer: the complexity oftargeted inhibitors.” Nat Rev Cancer (2005) 5: 341; Holbro, T. & Hynes,N. E. ErbB receptors: directing key signaling networks throughout life.Annu. Rev. Pharmacol. Toxicol. 44, 195-217 (2004); Hynes, N. E. & Stern,D. F. The biology of erbB-2/neu/HER-2 and its role in cancer. Biochim.Biophys. Acta 1198, 165-184 (1994)), and which is expressed at very lowlevels in non malignant tissues (Yamamoto et al; Nature. 1986 Jan.16-22;319(6050):230-4) (Press M. F et al., Oncogene (1990) 5:953).

According to other embodiments, the peptide ligand is capable of bindingin specific conditions the given receptor, which has at least 70%, 80%,90%, 85% or 100% homology, advantageously identity, with respect to agiven receptor chosen in the group consisting of: EGFR1 (epidermalgrowth factor receptor1) [Carpenter, G. (1992). Receptor tyrosine kinasesubstrates: src homology domains and signal transduction. Faseb J 6(14),3283-9], EGFR3 [Hynes, N. E., and Lane, H. A. (2005). ERBB receptors andcancer: the complexity of targeted inhibitors. Nat Rev Cancer 5(5),341-54], PMSA (antigen associated with the prostatic membrane), CEA(carcinoembrional antigen), GD2 (disialoganglioside, expressed inneuroblastoma and in melanoma), VEGF (vascular endothelial growthfactor) receptors 1 and 2 expressed in neovasculature [Carmeliet, P.(2005). VEGF as a key mediator of angiogenesis in cancer. Oncology 69Suppl 3, 4-10].

It is important to stress that, for some of the aforementioned receptorsnatural ligands are known, e.g EGF, VEGF. In the state of the art,monoclonal antibodies and single chain antibodies, which target receptorexpressed by diseased cells, are known. For example, J591, J415 e J533have been made (see the patent application having publication numberUS20030007974). Single chain antibodies to EGFR1 (Nakamura, T., Peng, K.W., Vongpunsawad, S., Harvey, M., Mizuguchi, H., Hayakawa, T., Cattaneo,R., and Russell, S. J. (2004). Antibody-targeted cell fusion. NatBiotechnol 22(3), 331-6), to EGFR3 (Horak, E., Heitner, T., Robinson, M.K., Simmons, H. H., Garrison, J., Russeva, M., Furmanova, P., Lou, J.,Zhou, Y., Yuan, Q. A., Weiner, L. M., Adams, G. P., and Marks, J. D.(2005). Isolation of scFvs to in vitro produced extracellular domains ofEGFR family members. Cancer Biother Radiopharm 20(6), 603-13), toVEGFR2/KDR (Δ7 scFv, Boldicke, T., Tesar, M., Griesel, C., Rohde, M.,Grone, H. J., Waltenberger, J., Kollet, O., Lapidot, T., Yayon, A., andWeich, H. (2001). Anti-VEGFR-2 scFvs for cell isolation. Single-chainantibodies recognizing the human vascular endothelial growth factorreceptor-2 (VEGFR-2/flk-1) on the surface of primary endothelial cellsand preselected CD34+ cells from cord blood. Stem Cells 19(1), 24-36)have been described.

Single chain antibodies against CEA have been prepared: inter alia, scFvMFE23 (which was disclosed in: Chowdhury et al, Retargeting Retrovirus,2004 Mol. Ther. 9:85, Imaging, Mayer A., Clin. Cancer. Res. 6 (5): 1711(2000), and in the patent application having publication numberUS20020090709) and scFv T84.66 (which was disclosed in: Hu, CancerResearch (1996) 56:3055; Olafsen T. et al., Protein Eng. Des. Sel.(2004) 17:21; Wong Y. J. et al., Clin. Cancer Res. (2004) 10:5014;Kenanova V. et al., Cancer Res. (2005) 65:622; US20030171551). Themonoclonal antibody MAb 3F8 (US20040116379, US20040115688, U.S. Pat. No.6,716,422, Kushner B. H. et al., (2001) 19:4189, Tur M. K. et al., Int.J. Molec. Med. (2001) 8:579, US20040180386) and the single chainantibody scFv 14.18 against GD2 are also known in the art.

According to some specific embodiments, the ligand has at least 70%,80%, 85%, 901, 951, 100% homology (advantageously identity) with aligand chosen in the group consisting of scFv J591, scFv MFE23, MAb 3F8,scFv T84.66 and scFv 14.18.

According to some embodiments, the ligand consists of at least threehundred aminoacids; advantageously at least three hundred and twenty,three hundred and sixty or two hundred and forty.

Advantageously, the ligand comprises a first domain (VL) and a seconddomain (VH) and a first linker (L1), which connects the first and thesecond domain (VL, VH) and is capable of allowing the first and thesecond domain (VL, VH) to take an adequate relative position; the firstand the second domain (VL, VH) being designed to bind said givenreceptor.

The ligand further comprises a second linker (L2) and/or a third linker(L3). The second domain (VH) being located between and connecting thefirst and the second linker (L1, L2). The first domain (VL) beinglocated between and connecting the first and the third linker (L1, L3).

The first domain (VL) consists of at least one hundred aminoacids,advantageously no more than one hundred and seventeen aminoacids. Thesecond domain (VH) consists of at least one hundred and ten,advantageously no more than one hundred and thirty, aminoacids. Thefirst linker (L1) consists of at least twelve, advantageously no morethan thirty, amino acids.

According to some embodiments, the first domain (VL) has at least 80%,90%, 951, 98%, 100% homology, advantageously identity, with respect toSEQ ID NO:2.

SEQ ID NO: 2 SDIQMTQSPS SLSASVGDRV TITCRASQDV NTAVAWYQQKPGKAPKLLIY SASFLYSGVP SRFSGSRSGT DFTLTISSLQPEDFATYYCQ QHYTTPPTFG QGTKVEI

According to some embodiments, the first domain (VL) has at least 80%,90%, 95%, 98% or 100% homology, advantageously identity, with respect toSEQ ID NO:3.

SEQ ID NO: 3 SEVQLVESGG GLVQPGGSLR LSCAASGFNI KDTYIHWVRQAPGKGLEWVA RIYPTNGYTR YADSVKGRFT ISADTSKNTAYLQMNSLRAE DTAVYYCSRW GGDGFYAMDY WGQGTLVTVS

According to some embodiments, the first linker (L1) has at least 50%,60%, 70%, 80%, 90%, 95%, 98% or 100% homology, advantageously identity,with respect to SEQ ID NO:4.

KSDMPMADPN RFRGKNLVFH SEQ ID NO: 4

According to some embodiments, the second linker (L2) has at least 50%,60%, 70%, 80%, 90%, 95%, 98% or 100% homology, advantageously identity,with respect to SEQ ID NO:5 or SEQ ID NO:8.

SSGGGSGSGG S SEQ ID NO: 5 SSGGGSGSGG SG SEQ ID NO: 8

According to some embodiments, the third linker (L3) consists of atleast two and, advantageously, no more than eight aminoacids. The thirdlinker (L3) has at least 50%, 60%, 70%, 80%, 90% or 100% homology,advantageously identity, with respect to SEQ ID or SEQ ID NO:7.

EN SEQ ID NO: 6 HSSGGGSG SEQ ID NO: 7

According to some particular embodiments, the peptide ligand is insertedin gD (glycoprotein D) of the glycoproteic envelope and a portion of gDis deleted so that the obtained modified gD has at least 70%, 80%, 90%,95%, 98% or 100% homology, advantageously identity, with respect to SEQID NO:10 or SEQ ID NO:9.

SEQ ID NO: 10 KYALADASLK MADPNRFRGK DLPVLDQLTD PPGVRRVYHIQAGLPDPFQP PSLPITVYYA HSSGGGSGSD IQMTQSPSSLSASVGDRVTI TCRASQDVNT AVAWYQQKPG KAPKLLIYSASFLYSGVPSR FSGSRSGTDF TLTISSLQPE DFATYYCQQHYTTPPTFGQG TKVEIKSDMP MADPNRFRGK NLVFHSEVQLVESGGGLVQP GGSLRLSCAA SGFNIKDTYI HWVRQAPGKGLEWVARIYPT NGYTRYADSV KGRFTISADT SKNTAYLQMNSLRAEDTAVY YCSRWGGDGF YAMDYWGQGT LVTVSSSGGGSGSGGSGMLP RFIPENQRTV AVYSLKIAGW HGPKAPYTSTLLPPELSETP NATQPELAPE DPEDSALLED PVGTVAPQIPPNWHIPSIQD AATPYHPPAT PNNMGLIAGA VGGSLLAALVICGIVYWMRR RTQKAPKRIR LPHIREDDQP SSHQPLFY SEQ ID NO: 9KYALAENSDI QMTQSPSSLS ASVGDRVTIT CRASQDVNTAVAWYQQKPGK APKLLIYSAS FLYSGVPSRF SGSRSGTDFTLTISSLQPED FATYYCQQHY TTPPTFGQGT KVEIKSDMPMADPNRFRGKN LVFHSEVQLV ESGGGLVQPG GSLRLSCAASGFNIKDTYIH WVRQAPGKGL EWVARIYPTN GYTRYADSVKGRFTISADTS KNTAYLQMNS LRAEDTAVYY CSRWGGDGFYAMDYWGQGTL VTVSSSGGGS GSGGSHIQAG LPDPFQPPSLPITVYYAVLE RACRSVLLNA PSEAPQIVRG ASEDVRKQPYNLTIAWFRMG GNCAIPITVM EYTECSYNKS LGACPIRTQPRWNYYDSFSA VSEDNLGFLM HAPAFETAGT YLRLVKINDWTEITQFILEH RAKGSCKYAL PLRIPPSACL SPQAYQQGVTVDSIGMLPRF IPENQRTVAV YSLKIAGWHG PKAPYTSTLLPPELSETPNA TQPELAPEDP EDSALLEDPV GTVAPQIPPNWHIPSIQDAA TPYHPPATPN NMGLIAGAVG GSLLAALVICGIVYWMRRRT QKAPKRIRLP HIREDDQPSS HQPLFY

The precursors of SEQ ID NO:10 and SEQ ID NO:9 may be expressed by SEQID NO:36 and SEQ ID NO:37, respectively.

The herein disclosed peptide sequences, in particular the modified gD,may be post-traslationally changed. Possible changes include, but arenot limited to glycosylation, pegylation, albumination, farnysylation,carboxylation, hydroxylation, phosphorylation.

In this regard it should be noted that, wild type gD has N-linkedoligosaccharides added at every specific consensus sequence (Asn-X-Serand/or Asn-X-Thr) (Sodora, D. L., G. H. Cohen, and R. J. Eisenberg.1989. Influence of asparagine-linked oligosaccharides on antigenicity,processing, and cell surface expression of herpes simplex virus type 1glycoprotein D. J Virol 63:5184-93) and possible O-linkedoligosaccharides added at one or more Ser and/or Thr residue.Advantageously, also the modified gD and/or the ligand include suchmodifications.

It has been experimentally seen that, surprisingly, the modified HSVaccording to the present invention, although the sequences aa 7-32, thatin wt gD are involved in the interaction with HVEM, were not alwaysdeleted, has lost not only the ability to interact with nectin1, butalso with HVEM, and is therefore detargeted from both natural receptorsHVEM and nectin1.

In this regard, it should be noted that, contrary to efforts describedby Zhou and Roizman (WO2004/033639), the used ligand (in this-case thescFv) is not inserted at the N-terminus of gD, but is inserted betweentwo portions of gD that contain residues that can not be deleted (namelythe N-terminus up to aa residue 60, and the region 218-end). Aparticular feature of the modified HSV is that these portions are linkedtogether in a single polypeptide chain, and are linked and heldtogether, in particular, by the scFv that, in this case, fulfillssimultaneously two functions (i) provides the new ligand for thereceptors to be targeted (and hence directs the tropism of therecombinant virus to the receptor of choice), and (ii) provides thescaffolding function that, in wt-gD, is located in the Ig-folded portionincluded in the polypeptide 61-218.

Further modifications that conceivably improve the ability of thetargeted virus to specifically attach to and enter cells that expressthe receptor targeted by the heterologous ligand include the removal ofspecific sequences in glycoprotein gB (aminoacid residues 68-77) and gC(aminoacid residues 136-152) that enable the binding to the non specificHSV receptor heparan sulphate. Such sequences, or extensions thereof,may be replaced with the heterologous ligand of choice, in order toconcentrate further the recombinant virus on the cells of choice.

A further implementation consists in the introduction in the viralgenome of mutations that greatly favour the spread of the virus from aninfected cell to a nearby adjacent cells. Mutations that exert sucheffect are known. Typically they cause the infected cells to form asyncytium (or polykaryocyte) with nearby cells, and are called syncytial(syn) mutations. Examples of such mutations are A40V located in gK andR858H, T813I, R796C located in gB.

In accordance with a further aspect of the present invention, there isprovided the above identified modified HSV for use as a medicament,advantageously for treating tumors; in particular, ovary tumor, mammarytumor, prostate tumor, colon tumor, stomach tumor, salivary gland tumor,melanoma, neuroblastoma, head and neck carcinoma, neoangiogenic tissue,in particular neoangiogenic tissues of a tumor, and/or metastasisthereof. Advantageously, the above defined modified HSV is used fortreating ovary tumor, mammary tumor, prostate tumor, stomach tumor,salivary gland tumor and metastasis thereof. Advantageously, the abovedefined modified HSV is provided for use in treating ovary tumor,mammary tumor and metastasis thereof.

In this regard, it is important to point out that the aforementionedmodified HSV is particularly useful for treating tumor metastasis. Thisis due to the fact that once the modified HSV is administered, itdiffuses and infects autonomously the metastasis.

The modified HSV may be administered to a subject by any known means. Inparticular, the modified HSV may be administered directly in the area ofa tumor or, alternatively, systemically, for example where metastasishave been detected or the tumor is not directly accessible.

Pharmaceutical preparations containing the modified HSV aresubstantially devoid of impurities that may cause damages to thesubject, in particular human beings or other mammals. Pharmaceuticalpreparations, advantageously, comprise one or more pharmaceuticallyacceptable excipients.

The modified HSV may be formulated for every known type ofadministration: in particular, for oral or parenteral or rectaladministration or in forms designed for inhalation or insufflation (bothby mouth and by nose). Formulation for parenteral use are advantageous.

For oral administration, the pharmaceutical preparations can be, forexample, in the form of tablets or capsules prepared using known methodswith excipients acceptable from a pharmaceutical point of view asbinding agents (for example pre-gelatised corn starch,polyvinylpyrrolidone or methylcellulose); fillers (for example lactose,microcrystalline cellulose or calcium hydrogen phosphate); additives(for example magnesium stearate, talc, silica); disintegrants (forexample potato starch); and/or lubricating agents (for example sodiumlauryl sulphate). The tablets can be coated with known methods. Liquidpreparations for oral administration may have the form, for example, ofsyrupy solutions or suspensions, or they can be in the form of a dryproduct which can be dissolved in water or in another liquid before use.These preparations can be prepared in known ways with pharmaceuticallyacceptable additives such as-suspending agents (for example sorbitol,cellulose derivatives, edible hydrogenated fats); emulsifying agents(for example lecithin or acacia); non aqueous liquids (for examplealmond oil, oily esters, ethyl alcohol or fractionated vegetable oils);and/or preservatives (for example methyl or propylp-hydroxybenzoates,sorbic acid or ascorbic acid). The preparations can also contain, inappropriate cases, buffering salts, colouring, aromatic and/orsweetening agents.

Preparations for oral administration can be formulated in a known way,so as to give a controlled release of the active compound.

The modified HSV can be formulated, in a known way, for parenteraladministration by injection or continuous administration. Formulae forinjection may be in the form of single doses, for example in ampoules ormultidose containers containing preservatives. The preparation may be inthe form of a suspension, in aqueous or oily liquids, and it may containformulation elements such as dispersing and stabilising agents.Alternatively, the active compound may be in powder form to be dissolvedimmediately before use in a suitable liquid, for example sterilisedwater.

The modified HSV can be formulated for rectal administration assuppositories or enteroclysis, for example containing excipients forsuppositories of a known type such as cocoa butter or other fats.

The modified HSV can also be formulated, in a known way, as preparationswith prolonged release. These preparations with prolonged release can beadministered by means of an implant (for example subcutaneous, orintramuscular) or by means of an intramuscular injection. So, forexample, the modified HSV can be formulated with suitable polymeric orhydrophobic materials (for example an emulsion or an oil) or resins withionic exchange, or relatively poorly soluble derivatives, such asrelatively poorly soluble salts.

For intranasal administration, the modified HSV can be formulated foradministration by means of a (known) device, for example in powder formwith a suitable carriers.

The dosages of the modified HSV may be defined as the number of plaqueforming unit (pfu). Example of dosages include 10³, 10⁴, 10⁵, 10⁶, 10⁷,10⁸, 10⁹, 10¹⁰, 10¹¹ pfu.

The subject to be treated may be any mammal, for example a human being.Other examples of animals that may be treated are: farm animals such ascattle, swine, goat, sheep, horse; pets such as cats and dogs; rabbit,mouse, rat.

In some cases it is possible to administer the modified HSV togetherwith further treatments of chemi-, immuno-, radio-therapy and/or othertypes of treatments.

In particular, the modified HSV may be used in combination withinhibitors of angiogenesis such as, for example: Endostatine (EntreMED),SU5416, SU666B (Sugen, San Francisco), Talidomide, COL-3 (Collagenex,Newton, Pa.), AG3340 (Agouron, LaJolla, Calif.), Marimastat (BritishBiotech), Neovastat (Aeterna, Quebec), BMS-275291 (Bristol-MyersSquibb).

In accordance with a further aspect of the present invention, there isprovided the use of a modified HSV for visualising a physiologicalcondition, advantageously for identifying tumor metastasis. Accordingly,it is herein provided the use of the modified HSV for preparing acomposition for visualising a physiological condition. Such acomposition may be prepared using known methods so that it can beadministered to a subject.

Advantageously, the visualization may be directed to: ovary tumor,mammary tumor, prostate tumor, colon tumor, stomach tumor, salivarygland tumor, melanoma, head and neck carcinoma, neoangiogenic tissue, inparticular neoangiogenic tissues of a tumor, and neuroblastoma and/ormetastasis thereof; advantageously, ovary tumor, mammary tumor, prostatetumor, stomach tumor, salivary gland tumor and metastasis thereof; inparticular, ovary tumor, mammary tumor and metastasis thereof.

The visualization of physiological conditions may be obtained by meansof imaging of the expression of the gene thymidine-kinase (TK) usingdetecting highly sensible techniques such as PET or SPECT (Sharma et al,Molecular imaging of gene expression and protein function in vivo withPET and SPECT, J. Magn. Reson. Imaging., 16(4):336-51, 2002) (Vries etal., Scintgraphic Imaging of HSV Gene Therapy, Curr. Pharm. Des.,8(16):1435-50, 2002) (Vries et al., Positron Emission Tomography:measurement of transgene expression, Methods, 27(3):234, 2002).

Alternatively it is possible to fuse a non-essential protein (forexample U_(s)11) and a reporter protein capable of being identified invivo (for example red or green fluorescent proteins or variationsthereof, luciferase or β-galactosidase).

Where the luciferase is used, its presence may be emphasized by means ofa suitable luminescent or chromatic substrate. The reporter protein maybe fused to a thymidine-kinase (Soling et al., Intercellularlocalization of Herpes simplex virus of the type 1 thymidine kinasefused to different fluorescent proteins depends on choice of fluorescenttag, FEBS Lett., 527(1-3):153, 2002).

In accordance with a further aspect of the present invention, there isprovided a process of preparing a modified HSV as above defined. Theprocess comprises an insertion phase, during which a nucleotide sequencecodifying the peptide ligand is inserted in the DNA of HSV so that theso obtained modified HSV expresses on its envelope the peptide ligand.

Advantageously, the DNA of the HSV is so manipulated that the gDcodifying sequence of the modified HSV has at least 70%, 80%, 90%, 95%or 100% homology, advantageously identity, with respect to SEQ ID NO:36or SEQ ID NO:37, in particular SEQ ID NO:37.

Before insertion suitable ligands, advantageously a single chainantibodies, may be identified using known techniques for testing theirability of binding at least one receptor expressed by the diseasedcells.

Further characteristics of the present invention will be clarified thefollowing description of some merely illustrative and non-limitingexamples.

EXAMPLE 1 Construction of HSV Expressing Genetically Modified gDsCarrying Deletions Substituted with a Single Chain Antibody Directed toHER2/Neu and Carrying EGFP as Reporter Gene

A) Deletion of gD from HSV-BAC.

To generate a gDminus virus, the “ET-cloning” procedure in bacteria wasperformed (Muyrers, J. P., Y. Zhang, G. Testa, and A. F. Stewart. 1999.Rapid modification of bacterial artificial chromosomes byET-recombination. Nucleic Acids Res 27:1555-7). A kanamycin resistancecassette flanked by two FRT sites was PCR amplified from the plasmidpFRT-2, with primers that contained at their 5′ ends 60 nt of sequencesflanking gD ORF: gDup_Kan_f (TGT TCG GTC ATA AGC TTC AGC GCG AAC GAC CAACTA CCC CGA TCA TCA GTT ATC CTT AAG CCA GTG AAT TCG AGC TCG GTA C) (SEQID NO:11) and gDdown_Kan_r (ACT TAT CGA CTG TCC ACC TTT CCC CCC TTC CAGACT CGC TTT ATA TGG AGT TAA GGT CCC GAC CAT GAT TAC GCC AAG CTC C) (SEQID NO:12). pFRT-2 was constructed by insertion of the kanamycinresistance derived from pCP15 into the NsiI sites of pCP16 replacing thetetracyclin resistance gene Cherepanov, P. P., and W. Wackernagel. 1995.Gene disruption in Escherichia coli: TcR and KmR cassettes with theoption of Flp-catalyzed excision of the antibiotic-resistancedeterminant. Gene 158:9-14. The PCR product was electroporated intoDH10B E. coli (Stratagene) harboring the YEbac102 HSV-BAC Tanaka, M., H.Kagawa, Y. Yamanashi, T. Sata, and Y. Kawaguchi. 2003. Construction ofan excisable bacterial artificial chromosome containing a full-lengthinfectious clone of herpes simplex virus type 1: viruses reconstitutedfrom the clone exhibit wild-type properties in vitro and in vivo. JVirol 77:1382-91, and transiently expressing lambda phage Red-β andRed-γ recombinases from pKD46 plasmid. Datsenko, K. A., and B. L.Wanner. 2000. one-step inactivation of chromosomal genes in Escherichiacoli K-12 using PCR products. Proc Natl Acad Sci USA 97:6640-5.Recombinant clones were selected on plates containing two antibiotics,25 μg/ml kanamycin (the marker contained in the PCR product) and 20μg/ml chloramphenicol (the marker contained into HSV-BAC sequences), toensure substitution of the gD coding sequence by the kanamycinresistance cassette. To remove the kanamycin cassette, the positiveclones were electroporated with pCP20 (Cherepanov, P. P., and W.Wackernagel. 1995. Gene disruption in Escherichia coli: TcR and KmRcassettes with the option of Flp-catalyzed excision of theantibiotic-resistance determinant. Gene 158:9-14), a plasmid expressingyeast FLP recombinase, which targets FRT sequences. Finally the colonieswere assayed for loss of the kanamycin marker and for chloramphenicolresistance. The resulting gDminus HSV-BAC genome, designated 102gD⁻FRT,was checked by Southern blot, PCR, sequencing, and for the ability toform plaques only in R6, and not in other cell lines.

B) Engineering of EGFP (Enhanced Green Fluorescent Protein) or LacZReporter Genes into 102gD⁻FRT HSV-BAC.

The second step in the engineering of HSV-BAC recombinants was theinsertion of the reporter gene EGFP or LacZ, thus generatinggDminus-EGFP-HSV-BAC or gDminus-LacZ-HSV-BAC. We chose as site ofreporter gene insertion the pBeloBAC sequences themselves, so that, themarker gene can be deleted together with the BAC sequences by Crerecombinase, if required (FIG. 1A). The coding sequence of EGFP followedby the polyadenylation signal from the bovine growth hormone (BGH) wasPCR amplified from pCMS-EGFP (Clontech) with primers EGFP_BamHI_f (CAACCC GGG ATC CAC CGG TCG CCA CCA TGG TGA GC) (SEQ ID NO:13) andEGFP+pA_BamHI_r (CCC CTT GGG ATC CTG CCC CAC CCC ACC CCC CAG AAT AG)(SEQ ID NO:14), and cloned downstream the HSV a27 promoter. The a27-EGFPcassette was inserted between two 700 by sequences, PCR amplified fromthe plasmid pBeloBac11 (GenBank Accession #: U51113). The twoaforementioned 700 by sequences were designated as pBeloBac11-up[primers Sal_pBelo_(—)1209_f: TTG CCA GTC GAC ATT CCG GAT GAG CAT TCATCA GGC GGG CA (SEQ ID NO:15) and pBelo_(—)1897_Xho_r: GCA AAA ACT CGAGTG TAG ACT TCC GTT GAA CTG ATG GAC (SEQ ID NO:16)] and pBeloBac11-down[primers Mun_pBelo_(—)1898_f: GGA AGT CAA TTG GAA GGT TTT TGC GCT GGATGT GGC TGC CC (SEQ ID NO:17) and pBelo_(—)2586_Eco_r: CAC ACT GAA TTCGCA ATT TGT CAC AAC ACC TTC TCT AGA AC (SEQ ID NO:18)]. In the resultingconstruct, the a27-EGFP cassette resulted inserted between nt 1897 and1898 (original coordinates) of pBeloBac11. The cassette a27-EGFP plusthe pBeloBac11 flanking sequences was subcloned in the shuttle vectorpST76KSR Adler, H., M. Messerle, M. Wagner, and U. H. Koszinowski. 2000.Cloning and mutagenesis of the murine gammaherpesvirus 68 genome as aninfectious bacterial artificial chromosome. J Virol 74:6964-74 forhomologous recombination in bacteria. For LacZ insertion, we followedthe same strategy, cloning pBeloBac11-up and -down sequences into aplasmid already containing the a27-LacZ cassette. The relevant insertand adjacent regions were sequenced for accuracy in all plasmids.

C) Construction of Shuttle Vectors for Insertion of Chimeric gD intogDminus BACs.

The gD shuttle vector named pS31 (FIG. 10) carries the scHER2L (scFvanti HER2 plus a 9-aa serine glycine Linker) inserted between aaresidues 24 and 25 of gD, plus the V34S substitution (FIG. 1B, b). Itwas constructed as follows. First, the V34S substitution was introducedby site directed mutagenesis in pLM13 (FIG. 8), a construct carryingscHER2L inserted between aa residues 24 and 25 of gD, generating pLM31(FIG. 9). Mutagenesis was performed by means of the StratageneQuickchange II kit (Stratagene) with primers gD_(—)34S_StuI 5′-TCC TCCGGG GAG CCG GCG CGT GTA CCA CAT CCA GGC AGG CCT ACC GG-3′ (SEQ ID NO:19)and its reverse. The primers contained the indicated silent restrictionsites, for ease of mutant clones screening. Next, the cassettecontaining the mutagenized gD+scHER2 plus gD genomic upstream anddownstream flanking sequences (about 500 by each) was transferred topST76KSR shuttle vector to enable homologous recombination in E. coli.

To construct pS39 (FIG. 11), the D215G, R222N, F223I substitutions wereadded to gD cloned in pS31 by means of the primergD_(—)215G-222N-223I_PvuI 5′-AGG GGG TGA CGG TGG GCT CGA TCG GGA TGC TGCCCA ACA TCA TCC CCG AGA ACC-3′ (SEQ ID NO:20) and its reverse (FIG. 1B,c).

The pS113 shuttle vector (FIG. 13) contains gD, in which aa residues6-38 were deleted and replaced with scHER2L [scFv anti HER2 followed bya 11 aa serine-glycine linker: SSGGGSGSGGS (SEQ ID NO:5), encoded by thesequence TCGAGTGGCGGTGGCTCTGGTTCCGGTGGATCC (SEQ ID NO:21)] (FIG. 1B, d).To generate this construct, EcoRI and BamHI restriction sites weresequentially introduced in gD ORF in pLM5 (FIG. 7). The EcoRIrestriction site was inserted in the aminoacid positions 6-8 of theprotein sequence and BamHI restriction site was inserted in the aminoacid positions 37-39 of the protein sequence, by means of the mutagenicprimers gD_(——)6/8_EcoRI_f 5′-CAA ATA TGC CTT GGC GGA GAA TTC TCT CAAGAT GGC CG-3′ (SEQ ID NO:22) and gD_(—)37/38_BamHI_f 5′-CGG GGG TCC GGCGCG GAT CCC ACA TCC AGG CGG G-3′ (SEQ ID NO:23), respectively. Theinsertion of the EcoRI site introduces the substitutions D6E and A7N.The scHER2L was amplified from pS2019a Sidhu, S. S., B. Li, Y. Chen, F.A. Fellouse, C. Eigenbrot, and G. Fuh. 2004. Phage-displayed antibodylibraries of synthetic heavy chain complementarity determining regions.J Mol Biol 338:299-310 with primers scFv_x6_Eco_f 5′-GCA AAG GAA TTC CGATAT CCA GAT GAC CCA GTC CCC G-3′ (SEQ ID NO:24) and scFv_SG_x37_BamH5′-CGG AGG ATC CAC CGG AAC CAG AGC CAC CGC CAC TCG AGG-3′ (SEQ IDNO:25). This construct was designated pLM113 (FIG. 12). The finalshuttle plasmid pS113 was constructed by subcloning the engineered gDalong with genomic flanking sequences (NruI-PmeI fragment) into pST76KSR(FIG. 13).

The pS249 shuttle vector contains gD, in which aa residues 61-218 weredeleted and replaced with LscHER2L [scFv anti HER2 flanked byserineglycine linkers, upstream 8 aa: HSSGGGSG (SEQ ID NO:7), encoded bythe sequence CATAGTAGTGGCGGTGGCTCTGGA (SEQ ID NO:26); downstream 12 aa:SSGGGSGSGGSG (SEQ ID NO:8), encoded by the sequenceTCGAGTGGCGGTGGCTCTGGTTCCGGTGGATCCGGT (SEQ ID NO:27)] in place of gD aaresidues 61 to 218 (FIG. 1B, e). Mutagenesis and cloning was performedon pLM5 (FIG. 7), a plasmid containing gD ORF cloned in pcDNA3.1(−)(Invitrogen), flanked by two 500-bp upstream and downstream genomicflanking sequences 15′ Menotti, L., A. Cerretani, and G.Campadelli-Fiume. 2006. A herpes simplex virus recombinant that exhibitsa single-chain antibody to HER2/neu enters cells through the mammarytumor receptor, independently of the gD receptors. J Virol 80:5531-9.First, two NdeI sites were inserted in the coding sequence replacing theamino acids 61-62 and 218-219 of mature gD, respectively, by usingmutagenic primers gD_(—)61/62_NdeI_f (5′-acg gtt tac tac gcc CAT Atg gagcgc gcc tgc c-3′) (SEQ ID NO:28) and gD_(—)218/219_NdeI_f (5′-GAC GGTGGA CAG CAT CCA TAT GCT GCC CCG CTT C-3′) (SEQ ID NO:29). Next, a 9 aaserine-glycine linker was inserted by annealing and ligating into theNdeI site the two phosphorylated oligos P-SG9Bam7/Nde_f (5′-TAG TAG TOGCGG TGG CTC TGG ATC CGG-3′) (SEQ ID NO:30) and P-SG9Bam7/Nde_r (5′-tACCGG AtC CAG AGC CAC CGC CAC Tac-3′) (SEQ ID NO:31), containing a silentBamHI site. The scHER2 was amplified from pS2019a Sidhu, S. S., B. L1,Y. Chen, F. A. Fellouse, C. Eigenbrot, and G. Fuh. 2004. Phage-displayedantibody libraries of synthetic heavy chain complementarity determiningregions. J Mol Biol 338:299-310 with primers scFv_Bam_f (5′-GGC TTA TGGATC CGA TAT CCA GAT GAC CCA GTC CCC-3′) (SEQ ID NO:32) andscFv_SG_x37_BamH_r (5′-CGG Agg atc cAC CGG AAC CAG AGC CAC CGC CAC TCGAGG-3′) (SEQ ID NO:33) and inserted into the BamHI site of theserine-glycine linker. The total insert length is of 801 bp, encoding267 aa residues. The construct was designated pLM249. Finally thecassette containing the engineered gDA61-218+fscHER2L plus gD genomicupstream and downstream flanking sequences (the NruI-PmeI fragment frompLM249) was subcloned into SmaI of pST76KSR shuttle vector generatingpS249 (FIG. 14) for homologous recombination in E. coli. The relevantinsert and adjacent regions were sequenced for accuracy in all plasmids.

D) Generation of recombinant genomes by two-step replacement inbacteria. The procedure applied to generate recombinant genomes in E.coli was essentially as described, with slight modifications O'Connor,M., M. Peifer, and W. Bender. 1989. Construction of large DNA segmentsin Escherichia coli. Science 244:1307-12; Messerle, M., I. Crnkovic, W.Hammerschmidt, H. Ziegler, and U. H. Koszinowski. 1997. Cloning andmutagenesis of a herpesvirus genome as an infectious bacterialartificial chromosome. Proc Natl Acad Sci USA 94:14759-63; Borst, E. M.,G. Hahn, U. H. Koszinowski, and M. Messerle. 1999. Cloning of the humancytomegalovirus (HCMV) genome as an infectious bacterial artificialchromosome in Escherichia coli: a new approach for construction of HCMVmutants. J Virol 73:8320-9. Briefly, electrocompetent DH10B E. coli(Stratagene) harbouring the relevant gDminus HSV-BAC genomes wereelectroporated with the shuttle vector in 0.2 cm electroporationcuvettes (Bio-Rad) at 200 O, 25 μF, 2.5 kV, plated on LB agar containing25 μg/ml Kana (the shuttle vector's marker) and 20 μg/ml Cam (the BAC'smarker Tanaka, M., H. Kagawa, Y. Yamanashi, T. Sata, and Y. Kawaguchi.2003. Construction of an excisable bacterial artificial chromosomecontaining a full-length infectious clone of herpes simplex virus type1: viruses reconstituted from the clone exhibit wild-type properties invitro and in vivo. J Virol 77:1382-91), and incubated at 30° C. o/n toallow the expression of RecA from the shuttle vector. The clones werere-plated onto LB+Kana+Cam at 43° C. to allow the identification ofthose harbouring the cointegrates (visible as large colonies, ascompared to the temperature sensitive “small colony” phenotypedetermined by non-integrated shuttle vectors). Subsequently, thecointegrates were allowed to resolve by plating the clones onto LB+Camat 30° C., and clones containing the resolved HSV-BAC were selected onLB+Cam plates supplemented with 10% sucrose. Finally, the clones werechecked for loss of Kana resistance, and for the presence of the desiredinsert by colony PCR.

Recombination between the 102gD⁻FRT HSV-BAC and the appropriate shuttlevectors generated gDminus-EGFP-HSV-BAC, or gDminus-LacZ-HSV-BAC DNAs,that contain the a27promoter-EGFP (or a27promoter-LacZ) cassetteinserted into the BAC sequences (FIG. 1A). The viruses werereconstituted by transfection of the BAC DNA in the gD-complementing R6cells.

The gDminus-HSV-BACs was used as recipient for the generation ofrecombinants containing the engineered gD. The recombinant genomes werechecked by PCR and sequencing. The viruses were reconstituted bytransfection of the BAC-DNAs into R6 cells Zhou, G., V. Galvan, G.Campadelli-Fiume, and B. Roizman. 2000. Glycoprotein D or J delivered intrans blocks apoptosis in SK-N-SH cells induced by a herpes simplexvirus 1 mutant lacking intact genes expressing both glycoproteins. JVirol 74:11782-91, followed by a single passage in BHK (baby hamsterkidney) cells, and subsequent growth in J-HER2 Menotti, L., A.Cerretani, and G. Campadelli-Fiume. 2006. A herpes simplex virusrecombinant that exhibits a single-chain antibody to HER2/neu enterscells through the mammary tumor receptor, independently of the gDreceptors. J Virol 80:5531-9 or SKOV3 (ATCC #HTB-77) cells. The virusstocks were grown in J-HER2 or SKOV3 cells and serially passaged formore than 10 passages. The virus titer was determined in SKOV3 cells.

EXAMPLE 2 Infection Assay with the R-LM31 Recombinant Carrying the V34SSubstitution in gD

The 1^(st) generation recombinants R-LM11 and R-LM11L carried scHER2inserted between aa residues 24 and 25 of gD Menotti, L., A. Cerretani,and G. Campadelli-Fiume. 2006. A herpes simplex virus recombinant thatexhibits a single-chain antibody to HER2/neu enters cells through themammary tumor receptor, independently of the gD receptors. J Virol80:5531-9. The insertion altered the N-terminus such that entry throughHVEM was hampered. Entry through nectin1 was maintained Menotti, L., A.Cerretani, and G. Campadelli-Fiume. 2006. A herpes simplex virusrecombinant that exhibits a single-chain antibody to HER2/neu enterscells through the mammary tumor receptor, independently of the gDreceptors. J Virol 80:5531-9. The first attempt to generate anectin1-detargeted recombinant consisted in the insertion of the V34Smutation in gD-scHER2 (FIG. 1 b). When introduced in the IL13-retargetedgD, the V34S substitution strongly decreased entry via nectin1 Zhou, G.,and B. Roizman. 2006. Construction and properties of a herpes simplexvirus 1 designed to enter cells solely via the IL-13alpha2 receptor.Proc Natl Acad Sci USA 103:5508-13. The recombinant LM31-BAC DNA wasgenerated by homologous recombination in E. coli. The recipient genomewas gDminus-LacZ-HSV-BAC. The R-LM31 recombinant virus was obtained bytransfection of the LM31-BAC DNA in the gD-complementing R6 cells.R-LM31 tropism was assayed in J cells expressing human or murinenectin1, or human HER2, and monitored as β-galactosidase activity. Asshown in FIG. 2A-D, the R-LM31 recombinant infected J-nectin1 cells(Cocchi, F., L. Menotti, P. Mirandola, M. Lopez, and G.Campadelli-Fiume. 1998. The ectodomain of a novel member of theimmunoglobulin superfamily related to the poliovirus receptor has theattributes of a bonafide receptor for herpes simplex viruses 1 and 2 inhuman cells. J Virol 72:9992-10002) (via either the human or murinereceptor); hence it was not detargeted from nectin1. The resultindicates that the effect of the V34S substitution varies depending onthe insert present in gD:

EXAMPLE 3 Electrophoretic Mobility of wt and Chimeric gDs Expressed inSKOV3 Cells

SKOV3 cells were infected with R-LM5 (the peptide sequence of gD ofR-LM5 is SEQ ID NO:1, whose precursor is expressed by the nucleotidesequence SEQ ID NO:35), R-LM13 (the peptide sequence of gD of R-LM13 isSEQ ID NO:42, whose precursor is expressed by the nucleotide sequenceSEQ ID NO:43), R-LM31 (the peptide sequence of gD of R-LM31 is SEQ IDNO:38, whose precursor is expressed by the nucleotide sequence SEQ IDNO:39), R-LM39 (the peptide sequence of gD of R-LM39 is SEQ ID NO:40,whose precursor is expressed by the nucleotide sequence SEQ ID NO:41),R-LM113 (SEQ ID NO:9) and R-LM249 at an m.o.i of 10 pfu/cell. 24 h laterinfected cell lysates were separated by SDS-PAGE, transferred tonitrocellulose membranes (Amersham), and visualized by Western blottingwith MAb BD80 against gD C-terminal portion of the ectodomain, followedby peroxidase-conjugated anti-mouse IgG and enhanced chemioluminescence(FIG. 2E). In the R-LM31 and R-LM39 recombinants the presence of scHER2Lresults in a slower migration, as in the R-LM13 prototype virus, ascompared to R-LM5 carrying wt-gD. In the R-LM113 recombinant theelectrophoretic mobility of chimeric gD is indistinguishable from thatof the R-LM13-31-39 recombinants'. In the R-LM249 recombinant, thereplacement of 158 aa residues of gD with LscHER2L results in amigration intermediate between wt gD and gD of R-LM113 (where 6-38 aaresidues of gD are replaced by scHER2L). R-LM113 produces less gD asR-LM5 or R-LM249, as the corresponding lane needed to be loaded with 10times as much lysate as compared to R-LM5 or R-LM249 to obtained thesignal observed in FIG. 2. This lower production of gD was previouslyreported for viruses carrying deletion in gD N-terminus Zhou, G., and B.Roizman. 2006. Construction and properties of a herpes simplex virus 1designed to enter cells solely via the IL-13alpha2 receptor. Proc NatlAcad Sci USA 103:5508-13.

EXAMPLE 4 Infection of an Array of Cells Lines by R-LM113 and R-LM249

Monolayers of an array of cell lines of rodent, simian or human originwere infected at increasing m.o.i, and EGFP reporter gene expression(Clontech) was measured 24 h later by means of a fluorometer. Digitalpictures were taken with a Kodak camera connected to a Zeiss Axioplanfluorescence microscope. R-LM113 and R-LM249 infected. J-HER2 cells, butnot J cells expressing human nectin1 or murine nectin1 as the solereceptor (FIG. 3). The detargeting from murine nectin1 was confirmed byfailure to infect L and NIH-3T3 cells. Human cells were susceptible toR-LM113 and R-LM249, provided that they expressed HER2 at high level(SKOV3). HER2-negative cells, e.g. HEp-2 ATCC #CCL-23, 1-143 tk⁻ (Post,L. E., and Roizman, B. (1981). A generalized technique for deletion ofspecific genes in large genomes: alpha gene 22 of herpes simplex virus 1is not essential for growth. Cell 25(1), 227-32.) and RH4(rhabdomyosarcoma) cells Ricci, C., L. Landuzzi, I. Rossi, C. DeGiovanni, G. Nicoletti, A. Astolfi, S. Pupa, S. Menard, K. Scotlandi, P.Nanni, and P. L. Lollini. 2000. Expression of HER/erbB family ofreceptor tyrosine kinases and induction of differentiation by glialgrowth factor 2 in human rhabdomyosarcoma cells. Int J Cancer 87:29-36,were infected to a negligible level. Interestingly, R-LM113 and R-LM249were specific for human HER2, as they failed to infect the TT12.E2 mousecell line expressing the rat ortholog of HER2 (neu-NT) De Giovanni, C.,G. Nicoletti, L. Landuzzi, A. Astolfi, S. Croci, A. Comes, S. Ferrini,R. Meazza, M. Iezzi, E. Di Carlo, P. Musiani, F. Cavallo, P. Nanni, andP. L. Lollini. 2004. Immunoprevention of HER-2/neu transgenic mammarycarcinoma through an interleukin 12-engineered allogeneic cell vaccine.Cancer Res 64:4001-9.

EXAMPLE 5 Virus Replication Assay

J, J-hNectin1, J-HVEM, J-HER2, SKOV3, 1-143 tk⁻ and HEp-2 cells grown in12-well plates were, infected with the viruses indicated in FIG. 4 at am.o.i. of 1 pfu/cell for 90 min at 37° C. Following virus adsorption,the inoculum was removed and the non penetrated virus was inactivated bymeans of an acid wash (40 mM citric acid, 10 mM KCl, 135 mM NaCl (pH 3))Brunetti, C. R., R. L. Burke, B. Hoflack, T. Ludwig, K. S. Dingwell, andD. C. Johnson. 1995. Role of mannose-6-phosphate receptors in herpessimplex virus entry into cells and cell-to-cell transmission. J Virol69:3517-28. Replicate cultures were frozen at the indicated times (3,24, 48 h) after infection. The viral progeny (intracellular plusextracellular) was titrated in SKOV3 cells.

The growth of R-LM39, R-LM113 and R-LM249 was compared to recombinantvirus R-LM5 (encoding wild type gD) and R-LM13 (encoding chimericgD-scHER2L without further mutations or deletions). (i) R-LM39 wasunable to grow in J-HVEM cells, but replicated in J-HER2 and inJ-nectin1 cells, implying that it could use both HER2 and nectin1 asreceptors (FIG. 4B, C, D). Accordingly, it replicated in the human celllines SKOV3 (that express both nectin1 and HER2), 1-143 tk⁻ and HEp-2cells (that express nectin1) (FIG. 4E, F, (ii) R-LM113 grew efficientlyin J-HER2 cells, better than R-LM249 and R-LM5 (FIG. 4D). In SKOV3 cellsR-LM113 and R-LM249 replicated to titers only 1 to 1.5 orders ofmagnitude lower than those of the control virus R-LM5 (FIG. 4E). (iii)R-LM113 and R-LM249 were detargeted from both nectin1 and HVEM, asassessed by its inability to grow in J-nectin1 and in J-HVEM cells, aswell as in the human 1-143 tk⁻ and HEp-2 to titers higher than10²-10³-10⁴ pfu/ml (FIG. 4B, C F, G).

EXAMPLE 6 Inhibition of Virus Infection by Antibodies

SKOV3 cells grown in 96-well plates were incubated for 2 h on ice withincreasing concentrations of antibodies (R1.302 to nectin1, Herceptin toHER2, or mouse immunoglobulins) diluted in DMEM without serum, and thenwith the viral inoculum at the m.o.i of 2 pfu/cell (as titered in SKOV3cells) for further 90 min on ice. Following virus adsorption, theunattached virus was removed and cells were washed twice with ice coldRPMI+Glutamax supplemented with 2.5% FBS. Cells were overlaid withmedium containing the same concentration of antibodies or IgGs, rapidlyshifted at 37° C., and incubated for 16 h. Infection was quantified as.EGFP fluorescence intensity by means of a Victor plate reader (PerkinElmer). The 100% value represents data obtained with cells infected withvirus, in the absence of antibodies.

Receptor usage was confirmed in virus blocking experiments withHerceptin, MAb R1.302, or mixture of the two antibodies. The results inFIG. 5 show that R-LM39 was not blocked by Herceptin or R1.302administered singly, but only by the two antibodies in combination (FIG.5A). The results imply that R-LM39 can use alternatively nectin1 or HER2as receptors, further documenting the lack of detargeting from nectin1.On the contrary R-LM113 and R-LM249 were blocked by Herceptin (FIGS. 5Band C). The combination of Herceptin plus MAb R1.302 exerted the sameinhibition as Herceptin alone; MAb R1.302 had no effect. R-LM113 orR-LM249 infection was inhibited by Herceptin alone, while MAb R1.302alone had no effect. We conclude that R-LM113 and R-LM249 can entercells only through the HER2 receptor, in accordance with the resultsshown in FIG. 4.

EXAMPLE 7 Inhibition of R-LM113 and R-LM249 Plaque Formation byHerceptin

We asked whether R-LM113 and R-LM249 used HER2 not only for virusinfection, but also for cell-to cell spread. SKOV3 cells were infectedwith serial dilutions of the indicated viruses and overlaid with mediumcontaining 1% Seaplaque agarose, with or without the addition of 10μg/ml Herceptin (MAb to HER2 Genentech). Fluorescent plaques weremonitored with a Zeiss fluorescence microscope, and pictures of 5plaques per sample were taken at 48 h after infection. The areas of theplaques were measured with Photoshop Histogram tool. As shown in FIG. 6,exposure of R-LM113- and R-LM249-infected SKOV3 monolayers to Herceptinreduced plaque size (in FIG. 6, −Herceptin indicates in the absence ofHerceptin; +Herceptin indicates in the presence of Herceptin. Plaquesize of R-LM5 and of the other non-detargeted viruses (R-LM13 andR-LM39) was not reduced by Herceptin.

EXAMPLE 8 Cytotoxic Activity of the Recombinant Viruses

We asked whether R-LM113 and R-LM249 maintained the cytotoxic activityof HSV-1 parental virus. SKOV3 cells were seeded in well plates (4×10⁵cells/well) and infected the following day with R-LM5, R-LM116 orR-LM249 at a m.o.i. of 3 pfu/cell. After three days the infected cellswere trypsinized, and the number of viable and nonviable cells wasdetermined by means of the Erythsosin B exclusion assay. Briefly, cellswere mixed 1:1 with 0.04% Erythrosin B (Sigma) in PBS, loaded on ahemocytometer and counted. Nonviable cells take up the stain and appearred in color. The number of nonviable cells was reported as a fractionof the total number of cells (red plus colorless). Cells detached fromthe monolayer and present in the supernatant of the infected sampleswere collected and counted in the same way. Replicate wells of noninfected cells were included as control. As shown FIG. 16, viralinfection almost prevents cells from dividing, as the total number ofcells is lower as compared to non infected cells. Moreover infectioncauses cell cytotoxicity, as the percentage of nonviable cells is higherin infected cultures with respect to non infected replicate cultures.The effect of infection of the R-LM113 and R-LM249 recombinants iscomparable to that of R-LM5 virus, carrying wild type gD, indicatingthat the retargeting and detargeting of the virus did not affect thecytotoxic properties of the recombinants.

1. Modified herpes simplex virus (HSV) comprises a glycoproteicenvelope, which has an heterologous peptide ligand capable of binding inspecific conditions a given receptor expressed by diseased cells andsubstantially not expressed by non-diseased cells; the glycoproteicenvelope being so modified that the capability of the modified HSV ofinteracting with receptor nectin1/HveC is reduced.
 2. Modified HSVaccording to claim 1, wherein the glycoproteic envelope being somodified that the capability of the modified HSV of interacting withreceptors HVEM/HveA and nectin1/HveC is reduced, in particular whereinthe glycoproteic envelope being so modified that the capability of themodified HSV of interacting with receptors HVEM/HveA and nectin1/HveC issubstantially ablated.
 3. Modified HSV according to claim 1, wherein thepeptide ligand is inserted in gD (glycoprotein D) of the glycoproteicenvelope of HSV; a portion of gD being deleted.
 4. Modified HSVaccording to claim 1, wherein a portion of gD of the glycoproteicenvelope of HSV is deleted; said deleted portion being selected from agroup consisting of: portions extending between positions correspondingto 1 to 8, on the one side, and 38 to 55, on the other side; portionsextends between positions corresponding to 40 to 61, on the one side,and 210 to 218, on the other side preferably wherein the deleted portionextends between positions corresponding to 61, on the one side, and 218,on the other side, or wherein the deleted portion extends betweenpositions corresponding to 6, on the one side, and 38, on the otherside.
 5. Modified HSV according to claim 3, wherein the peptide ligandis inserted in place of the deleted portion.
 6. Modified HSV accordingto claim 1, wherein the peptide ligand and gD form a fusion protein. 7.Modified HSV according to claim 3, wherein gD has at least 80% homologywith respect to SEQ ID NO:
 1. 8. Modified HSV according to claim 1,wherein said given receptor has at least 90% homology with respect toreceptor HER2/ErbB2 in particular wherein said given receptor isHER2/ErbB2.
 9. Modified HSV according to claim 1, wherein the peptideligand is capable of binding in specific conditions the given receptorchosen in the group consisting of: EGFRVEGFR, PMSA, CEA, GD2, VEGFR1 and2.
 10. Modified HSV according to claim 1, wherein the peptide ligand isa single chain antibody and in particular consists of at least threehundred aminoacids.
 11. Modified HSV according to claim 10, wherein thesingle chain antibody comprises a first domain (VL) and a second domain(VH) and a first linker (L1), which is located between and connects thefirst and the second domain (VL, VH) and is capable of allowing thefirst and the second domain (VL, VH) to take an adequate relativeposition; the first and the second domain (VL, VH) being designed tobind in specific conditions said given receptor, preferably wherein thesingle chain antibody comprises a second linker (L2); the second domain(VH) being located between and connecting the first and the secondlinker (L1, L2), a third linker (L3); the first domain (VL) beinglocated between and connecting the first and the third linker (L1, L3)or a combination of said second linker (L2) and said third linker (L3).12. Modified HSV according to claim 11, wherein the first domain (VL)consists of at least one hundred aminoacids, in particular no more thanone hundred and seventeen aminoacids; the second domain (VH) consistingof at least one hundred and ten, in particular no more than one hundredand thirty, aminoacids,—the first linker (L1) consisting of at leasttwelve, in particular no more than thirty, aminoacids.
 13. Modified HSVaccording to claim 11, wherein the first domain (VL) has at least 80%homology, in particular identity, with respect to SEQ ID NO: 2; thesecond domain (VH) having at least 80% homology, in particular identity,with respect to SEQ ID NO: 3 preferably wherein the first domain (VL)has at least 90% homology, in particular identity, with respect to SEQID NO: 2; the second domain (VH) having at least 90% homology, inparticular identity, with SEQ ID NO: 3, more preferably wherein thefirst domain (VL) has at least 95% homology with respect to SEQ ID NO:2; the second domain (VH) having at least 95% homology with SEQ ID NO: 3in particular wherein the first domain (VL) consists of SEQ ID NO: 2;the second domain (VH) consists of SEQ ID NO:
 3. 14. Modified HSVaccording to claim 11, wherein the first linker (L1) has at least 50%homology with respect to SEQ ID NO: 4, in particular wherein the firstlinker (L1) has at least 80% homology with respect to SEQ ID NO:
 4. 15.Modified HSV according to claim 11, wherein the second linker (L2) hasat least 50% homology with respect to SEQ ID NO:
 5. 16. Modified HSVaccording to claim 11, wherein the third linker (L3) consists of atleast two and no more than eight aminoacids, in particular wherein thethird linker (L3) is chosen in a group consisting of: a peptide sequencehaving at least 50% homology with respect to SEQ ID NO: 6, a peptidesequence having at least 50% homology with respect to SEQ ID NO:
 7. 17.Modified HSV according to claim 1, wherein the peptide ligand isinserted in gD (glycoprotein D) of the glycoproteic envelope and aportion of gD is deleted so that the obtained modified gD is chosen in agroup consisting of: a sequence having at least 70% homology, inparticular identity, with respect to SEQ ID NO: 10, a sequence having atleast 70% homology, in particular identity, with respect to SEQ ID NO:9, preferably wherein the modified gD is chosen in a group consistingof: a sequence having at least 80% homology with respect to SEQ ID NO:10, a sequence having at least 80% homology, with respect to SEQ ID NO:9, in particular wherein the modified gD is chosen in a group consistingof: a sequence having at least 100% homology, in particular identity,with respect to SEQ ID NO: 10, a sequence having at least 100% homology,in particular identity, with respect to SEQ ID NO:
 9. 18. Modified HSVaccording to claim 1, wherein the modified gD is N-glycosylated atconsensus sequences Asn-X-Ser and/or Asn-X-Thr and possiblyO-glycosylated at one or more Ser and/or Thr residue.
 19. Modified HSVaccording to claim 1, and comprising a marker.
 20. Modified HSVaccording to claim 1, for use as a medicament.
 21. Modified HSVaccording to claim 1, for treating a tumor disease, in particular fortreating an ovary tumor, a mammary tumor, a disease selected from agroup consisting of: prostate tumor, colon tumor, melanoma,neuroblastoma, head and neck carcinoma, stomach tumor, salivary glandtumor and neoangiogenic tissue, or a metastasis of a tumor, inparticular a tumor selected from the group consisting of: ovary tumor,mammary tumor, prostate tumor, colon tumor, melanoma and neuroblastoma.22. Use of a modified HSV according to claim 19, for visualizing aphysiological condition.
 23. Pharmaceutical preparation comprising amodified HSV according to claim 1 and at least a pharmaceuticalacceptable excipient.
 24. Method of treating a tumor comprising theadministration of an effective amount of a modified HSV according toclaim 1, in particular wherein the tumor is selected from the group:stomach tumor, salivary gland tumor, ovary tumor, mammary tumor,prostate tumor, head and neck carcinoma, colon tumor, melanoma,neuroblastoma, and neoangiogenic tissue, in particular neoangiogenictissues of a tumor.
 25. Process of preparing a modified HSV inaccordance with claim 1, the process comprising an insertion phase,during which a nucleotide sequence codifying the ligand is inserted inthe DNA of HSV so that the so obtained modified HSV expresses on itsenvelope the ligand, in particular further comprising one or both of thesteps selected from the group consisting of: (a) a deletion step, duringwhich a portion of said DNA is deleted, and (b) a determination step,which is before the insertion step and during which said ligand, inparticular a single chain antibody, is identified, in particularwherein, during the determination step, ligands, in particular singlechain antibodies, are obtained and their ability of binding at least onereceptor expressed by the diseased cells is tested. 26-54. (canceled)